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Magnolia kobus

Kobus Magnolia · Kobushi Magnolia · Northern Japanese Magnolia

Family MagnoliaceaeGenus Magnolia

A broad low-branched tree covered in white blossom, standing above a pond bank
The whole plantBruce MarlinCC BY-SA 3.0

About the plant

What it is and where it grows — not part of any germination protocol.

The plant

Habit
shrub or treePlants of the World Online
Habit
Perennial, Shrub, TreePLANTS Database
Height
25-30 ft7.6-9.1 mExtension Gardener Plant Toolbox
Spread
25-35 ft8-11 mExtension Gardener Plant Toolbox
Flower
Pink, Red/Burgundy, WhiteExtension Gardener Plant Toolbox
Blooms
SpringExtension Gardener Plant Toolbox
Native range
Japan, KoreaGBIF Backbone Taxonomy
Hardiness zones
4-8Extension Gardener Plant Toolbox

Growing conditions

Sun
Full sun; Partial ShadeExtension Gardener Plant Toolbox
Soil
Clay, High Organic Matter, Loam (Silt)Extension Gardener Plant Toolbox
Soil pH
Alkaline (>8.0), Neutral (6.0-8.0)Extension Gardener Plant Toolbox
Moisture
Good Drainage, MoistExtension Gardener Plant Toolbox

Toxicity is noted only where a source states it. No note here is not a finding of safety.

Sources: Plants of the World Online — Royal Botanic Gardens, Kew; PLANTS Database — USDA NRCS; Extension Gardener Plant Toolbox — NC State Extension; GBIF Backbone Taxonomy — Global Biodiversity Information Facility.

Worth knowing

Two sources report 9 treatments between them. All are shown.

Protocol 1

DerivedN. C. Deno, 1996

Difficulty High Rated by us, not by the source.

Start around December 8, 2026 for a May 3 last frost.

  1. Clean the flesh off the seed

  2. Leach in running water

    Duration: 7 days

    Washed and cleaned daily for 7 days.

  3. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  4. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  5. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  6. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

    12 germinated in this phase.

Steps after step 4 run on after germination.

about 3 months from start to step 4. Germination happens during step 4, in 21 days.

54% germination in 7–21 days.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Magnolia p. 56Public domain
Show the original text
Magnolia (Magnoliaceae). M. kobus v. stellata has germination initiated by GA-3, but 40-70 is satisfactory and probably preferable. Seeds WC 7 d germ. 70 GA-3(50% in 3rd w), 70-40-70(50% in 10-17 d), and 40-70(54% in 1-3 w)-40-70(12% in 2-4 w).
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Magnolia p. 56. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

Protocol 2

DerivedN. C. Deno, 1996

Difficulty Moderate Rated by us, not by the source.

Start around March 8, 2027 for a May 3 last frost.

  1. Clean the flesh off the seed

  2. Leach in running water

    Duration: 7 days

    Washed and cleaned daily for 7 days.

  3. Gibberellic acid soak

  4. Sow and cover

    Temperature: 70°F 21°C

7 days from start to sowing. Then 21 days to germinate.

50% germination in 21 days.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Magnolia p. 56Public domain
Show the original text
Magnolia (Magnoliaceae). M. kobus v. stellata has germination initiated by GA-3, but 40-70 is satisfactory and probably preferable. Seeds WC 7 d germ. 70 GA-3(50% in 3rd w), 70-40-70(50% in 10-17 d), and 40-70(54% in 1-3 w)-40-70(12% in 2-4 w).
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Magnolia p. 56. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

Protocol 3

DerivedN. C. Deno, 1996

Difficulty High Rated by us, not by the source.

Start around September 14, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 13, 2026.

  1. Clean the flesh off the seed

  2. Leach in running water

    Duration: 7 days

    Washed and cleaned daily for 7 days.

  3. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  4. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  5. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

about 6 months from start to step 5. Germination happens during step 5, in 17 days.

50% germination in 10–17 days.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Magnolia p. 56Public domain
Show the original text
Magnolia (Magnoliaceae). M. kobus v. stellata has germination initiated by GA-3, but 40-70 is satisfactory and probably preferable. Seeds WC 7 d germ. 70 GA-3(50% in 3rd w), 70-40-70(50% in 10-17 d), and 40-70(54% in 1-3 w)-40-70(12% in 2-4 w).
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Magnolia p. 56. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

Protocol 4

DerivedN. C. Deno, 1993

Difficulty High Rated by us, not by the source.

Start around December 15, 2026 for a May 3 last frost.

  1. Clean the flesh off the seed

  2. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  3. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  4. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  5. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

    20 germinated in this phase.

Steps after step 3 run on after germination.

about 3 months from start to step 3. Germination happens during step 3, in 21 days.

40% germination in 7–21 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Magnolia p. 175Public domain
Show the original text
Magnolia (Magnoliaceae). Seeds are enclosed in an oily red berry, and were WC with daily brief detergent washes. Germinations might have been improved if there had been exteneded detergent washes. Empty seed coats make seed counts inaccurate. Germination is epigeal and the cotyledons develop in 1-3 w after germination. Outdoor treatment killed the seeds and seeds of M. kobus var. stellata germ. 40-70(40% in 1-3 w)-40-70(20%), 70-40-70(3%), and none in outdoor treatment. Seed DS 6 m at 70 germ. 70-40(2/13)-70(1/13)-4o- 70(2/13) and 40-70(6/18)-40-70.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Magnolia p. 175. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

Protocol 5

DerivedN. C. Deno, 1993

Difficulty High Rated by us, not by the source.

Start around June 19, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on June 18, 2026.

  1. Clean the flesh off the seed

  2. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  3. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  4. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  5. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  6. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

Steps after step 4 run on after germination.

about 9 months from start to step 4. Germination happens during step 4; time not stated, 21 days assumed.

33% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Magnolia p. 175Public domain
Show the original text
Magnolia (Magnoliaceae). Seeds are enclosed in an oily red berry, and were WC with daily brief detergent washes. Germinations might have been improved if there had been exteneded detergent washes. Empty seed coats make seed counts inaccurate. Germination is epigeal and the cotyledons develop in 1-3 w after germination. Outdoor treatment killed the seeds and seeds of M. kobus var. stellata germ. 40-70(40% in 1-3 w)-40-70(20%), 70-40-70(3%), and none in outdoor treatment. Seed DS 6 m at 70 germ. 70-40(2/13)-70(1/13)-4o- 70(2/13) and 40-70(6/18)-40-70.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Magnolia p. 175. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

Protocol 6

DerivedN. C. Deno, 1993

Difficulty High Rated by us, not by the source.

Start around September 17, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 16, 2026.

  1. Clean the flesh off the seed

  2. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  3. Sow and cover

    Temperature: 70°F 21°C

about 6 months from start to sowing. Germination time not stated; 21 days assumed.

15% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Magnolia p. 175Public domain
Show the original text
Magnolia (Magnoliaceae). Seeds are enclosed in an oily red berry, and were WC with daily brief detergent washes. Germinations might have been improved if there had been exteneded detergent washes. Empty seed coats make seed counts inaccurate. Germination is epigeal and the cotyledons develop in 1-3 w after germination. Outdoor treatment killed the seeds and seeds of M. kobus var. stellata germ. 40-70(40% in 1-3 w)-40-70(20%), 70-40-70(3%), and none in outdoor treatment. Seed DS 6 m at 70 germ. 70-40(2/13)-70(1/13)-4o- 70(2/13) and 40-70(6/18)-40-70.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Magnolia p. 175. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

Protocol 7

DerivedN. C. Deno, 1993

Difficulty High Rated by us, not by the source.

Start around June 19, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on June 18, 2026.

  1. Clean the flesh off the seed

  2. Dry storage

    Duration: 180 daysTemperature: 70°F 21°C

  3. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  4. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  5. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

    1/13 germinated in this phase.

Steps after step 4 run on after germination.

about 9 months from start to step 4. Germination happens during step 4; time not stated, 21 days assumed.

15% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Magnolia p. 175Public domain
Show the original text
Magnolia (Magnoliaceae). Seeds are enclosed in an oily red berry, and were WC with daily brief detergent washes. Germinations might have been improved if there had been exteneded detergent washes. Empty seed coats make seed counts inaccurate. Germination is epigeal and the cotyledons develop in 1-3 w after germination. Outdoor treatment killed the seeds and seeds of M. kobus var. stellata germ. 40-70(40% in 1-3 w)-40-70(20%), 70-40-70(3%), and none in outdoor treatment. Seed DS 6 m at 70 germ. 70-40(2/13)-70(1/13)-4o- 70(2/13) and 40-70(6/18)-40-70.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Magnolia p. 175. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

Protocol 8

DerivedN. C. Deno, 1993

Difficulty Very high Rated by us, not by the source.

Start around September 17, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on September 16, 2026.

  1. Clean the flesh off the seed

  2. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

  3. Cold moist stratification

    Duration: 90 daysTemperature: 40°F 4°C

  4. Warm moist stratification

    Duration: 90 daysTemperature: 70°F 21°C

about 6 months from start to step 4. Germination happens during step 4; time not stated, 21 days assumed.

3% germination.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Magnolia p. 175Public domain
Show the original text
Magnolia (Magnoliaceae). Seeds are enclosed in an oily red berry, and were WC with daily brief detergent washes. Germinations might have been improved if there had been exteneded detergent washes. Empty seed coats make seed counts inaccurate. Germination is epigeal and the cotyledons develop in 1-3 w after germination. Outdoor treatment killed the seeds and seeds of M. kobus var. stellata germ. 40-70(40% in 1-3 w)-40-70(20%), 70-40-70(3%), and none in outdoor treatment. Seed DS 6 m at 70 germ. 70-40(2/13)-70(1/13)-4o- 70(2/13) and 40-70(6/18)-40-70.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Magnolia p. 175. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

Protocol 9

DerivedN. C. Deno, 1993

Difficulty Very high Rated by us, not by the source.

  1. Clean the flesh off the seed

  2. Sow outdoors and leave it

    Nothing germinated outdoors.

No stated waiting before sowing.

0% germination.

This source doesn't state how long step 2 lasts.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Magnolia p. 175Public domain
Show the original text
Magnolia (Magnoliaceae). Seeds are enclosed in an oily red berry, and were WC with daily brief detergent washes. Germinations might have been improved if there had been exteneded detergent washes. Empty seed coats make seed counts inaccurate. Germination is epigeal and the cotyledons develop in 1-3 w after germination. Outdoor treatment killed the seeds and seeds of M. kobus var. stellata germ. 40-70(40% in 1-3 w)-40-70(20%), 70-40-70(3%), and none in outdoor treatment. Seed DS 6 m at 70 germ. 70-40(2/13)-70(1/13)-4o- 70(2/13) and 40-70(6/18)-40-70.
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Magnolia p. 175. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

How each step is done, in Deno’s words, and what Verified and Derived mean.

Germination trials

Readers’ own records of sowing this species, published after review. Share your trial · All trials

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